For over 70 years pre-fabricated denture teeth have been used to construct dentures. The teeth are manufactured from porcelain, plastic or composite materials. Many different shapes of teeth have been developed and patented to address specific treatment requirements. Construction of dentures with pre-fabricated teeth has many advantages over custom hand made teeth. The teeth are manufactured from specific molds and are of a consistent shape and quality. The porcelain or plastic materials can be made under controlled manufacturing conditions. The aesthetic appearance of the teeth is consistent and does not require carving the tooth form by hand. Unfortunately, there are problems with pre-fabricated teeth because the teeth are not custom made for each patient. As a result, hand grinding of the biting surfaces is often required to properly position the teeth for any given patient. It is also frequently necessary to grind the retentive surfaces of the teeth to allow them to fit to the shape of the residual alveolar ridge after natural teeth have been removed. Hand grinding is also required if the denture teeth are to fit to implant retained components. Denture teeth also frequently move during the process of packing and processing the denture base material to the denture teeth. This movement is called “processing error” and is corrected by hand grinding the teeth after processing.
Conventional Dentures
The selection of pre-fabricated denture teeth is usually based on the aesthetic requirements of the patient along with the form of the residual ridge and the muscular co-ordination of the patient. Some common types of teeth are: zero degree mono-plane teeth, anatomic teeth or teeth designed for “lingulalized occlusion.” In the process of making dentures, a master impression is made of the upper and lower residual ridge and a dental cast is made by pouring a plaster type material into the impression to create a dental cast or model of the patient's mouth. This cast is then used to make record bases. Record bases are made of a light cured composite resin or autopolymerizing acrylic resin to provide a base to position and hold the artificial teeth in wax. In present art, each type of tooth is hand ground and set in a specific relationship to the residual alveolar ridge and the dental technician must carefully place each tooth in wax to maintain its ideal “set-up.” This is a time consuming process well known in the art. If the teeth are to be set to a flat plane then a flat metal or plastic plate is used to position the biting surface of the tooth. If a balanced “lingualized occlusion” is used, teeth with prominent upper lingual cusps are set to a curved template with a radius of around 4 inches. Many different mechanical and anatomic reference points, planes and surfaces have been used to position artificial teeth by hand. The teeth are set in wax to maintain their position in relation to the record bases and to allow for a wax “try-in” which is an opportunity to try the tooth set-up in the patient's mouth to evaluate aesthetics and the position of the teeth. Wax is soft and can change shape when heated. Frequently denture teeth imbedded in wax will move even after being set in an ideal position. After the wax “try-in,” the dentures are made by investing the teeth, wax and record base in a flask and heating it in a water bath to remove the wax and record base. The remaining space is filled with a heat or autopolymerizing denture base material. Processing the dentures causes the denture teeth to move during curing and after the base material has been processed to the teeth, a technician hand grinds the teeth to correct processing errors.
Immediate Dentures
Immediate dentures are made for patients that have many of their natural teeth, but the teeth are “hopeless” and will need to be surgically removed. Since most patients do not want to go without teeth during the period of healing, immediate dentures are made before the natural teeth have been extracted and are inserted at the time of surgery. The “set-up” of the artificial teeth can not be tried in the patient's mouth since the natural teeth are still present and the proper spatial position of the teeth in relation to the midline, anatomic landmarks and the opposing teeth is more difficult to determine. When making immediate dentures, the dental technician hand grinds the plaster cast of the patient's mouth to selectively remove the plaster teeth. This creates a cast that has a shape similar to the patient's mouth at the time of surgery after the teeth have been removed. The present laboratory process has some “guess work” since the dental technician does not know the shape of the bone supporting the teeth under the gum. These problems make immediate denture construction less predictable and more complex than conventional denture construction.
Conventional methods of constructing dentures may be labor intense, complex, and imprecise. There is a need for an improved denture tooth system and method that addresses these or other shortcomings in the prior art.